Memory for emotionally arousing events over time in Autism Spectrum Disorder

Emotionally arousing events are typically better remembered and more resistant to forgetting than neutral events. Findings from word list paradigms suggest that this may not hold for individuals with Autism Spectrum Disorder (ASD), who also tend to be less accurate as eyewitnesses under some circumstances. To test whether attenuated effects of arousal on memory may be responsible for poorer eyewitness testimonies in ASD, we asked adults with and without the disorder to view either arousing or neutral versions of a narrated slide sequence (Experiment 1) or video clip (Experiment 2) before assessing their memory for the material. Both groups exhibited increases in psychophysiological arousal during the arousing compared with the neutral version of the narratives, and both groups also demonstrated a memory advantage for the arousing events. Contrary to predictions, these observations indicate that stimulus induced arousal modulates memory for naturalistic events relatively typically in ASD. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Memory for traumatic events

This research compares memory for traumatic events with memory for non-traumatic versions of the same event. In Experiment 1, subjects watched an event depicted in slides while focusing and rehearsing the central detail of each slide. They were tested after a short or a longer retention interval (20 min or 2 weeks). Subjects who watched the traumatic version were better able to recall the central details that they had rehearsed, but were less well able to recognize the specific slides that they saw. Better recall for the traumatic group did not occur because the words used to describe the recalled details were inherently more memorable, as shown in Experiment 2. In Experiment 3, subjects watched either a traumatic or non-traumatic version of a filmed event and about 6 months later they were asked to remember the essence of the film. Subjects who saw the traumatic version were better able to recall the essence of the film. A similar finding was obtained with a group of subjects from Experiment 1 who were also contacted about 6 months after their initial participation. These results suggest that some information (the essence, the theme) of a traumatic event might be relatively well retained in memory, while memory is impaired for many of the specific, and especially peripheral, details.     

Memory for time and place contributes to enhanced confidence in memories for emotional events

Emotion strengthens the subjective sense of remembering. However, these confidently remembered emotional memories have not been found be more accurate for some types of contextual details. We investigated whether the subjective sense of recollecting negative stimuli is coupled with enhanced memory accuracy for three specific types of central contextual details using the remember/know paradigm and confidence ratings. Our results indicate that the subjective sense of remembering is indeed coupled with better recollection of spatial location and temporal context, but not higher memory accuracy for colored dots placed in the conceptual center of negative and neutral scenes. These findings show that the enhanced subjective recollective experience for negative stimuli reliably indicates objective recollection for spatial location and temporal context, but not for other types of details, whereas for neutral stimuli, the subjective sense of remembering is coupled with all the types of details assessed. Translating this finding to flashbulb memories, we found that, over time, more participants correctly remembered the location where they learned about the terrorist attacks on 9/11 than any other canonical feature. Likewise, participants' confidence was higher in their memory for location versus other canonical features. These findings indicate that the strong recollective experience of a negative event corresponds to an accurate memory for some kinds of contextual details but not for other kinds. This discrepancy provides further evidence that the subjective sense of remembering negative events is driven by a different mechanism than the subjective sense of remembering neutral events.     

Memory for thematically arousing events

Many studies have indicated that emotional arousal improves memory for the center, or gist, of an event but undermines memory for the event's periphery. However, all of these studies have elicited emotion by showing participants some salient visual stimulus intended to arouse them (e.g., the sight of a wound). This stimulus may have served as an attention magnet, and this, not the arousal, may have been the cause of the observed narrowing of memory. In this article, we examine how participants remember events that involve thematically induced arousal, arousal produced by empathy, rather than by a visual emotional stimulus. The data show that emotionality improves memory for all aspects of these events, with no memory narrowing.     

Memory for unique personal events: The roommate study

Memory for naturally occurring episodic events was measured along with memory for the date of occurrence of those events. The effect of rehearsal was also measured. Participants in the experiment recorded unique personal events for themselves and their roommates for a semester (data were collected for approximately 14 weeks). They also rated the memorability of the events at the time the events were recorded. The roommates were unaware that they were to be tested on the events until approximately I week before the memory test. Accuracy in dating events decreased at the rate of roughly 1 day every week of the retention interval. Events rated as memorable were encoded better than events rated as unmemorable but were forgotten at the same rate. Increasing rehearsal decreased the rate of forgetting the events. Although the recorders selected the events to be recorded and knew they were to be tested on those events, they did not differ from their roommates on any of the memory measures     

Memory for action events: findings in neurological patients

Encoding action phrases by enacting leads normally to better memory performance than verbal encoding. In order to gain additional insight into the representational basis of the enactment effect, neurological patients are contrasted with healthy participants. Persons suffering from Parkinson's disease, which primarily impairs the motor system, and patients suffering from Frontal Lobe Syndrome, which primarily affects action-related planning processes, were involved. We investigated whether the enactment effect would be differentially affected by these disorders. In addition, the characteristics of information processing after encoding by enacting was analyzed by varying memory material (unrelated versus clusterable actions) and by adding an encoding condition that included obligatory action planning (director condition). The findings indicate that the impact of motor information for the enactment effect is not dominant compared to the role of action-related cognitive and motivational processes, in particular planning processes. The findings of the two experiments are explained within traditional conceptual memory theories.     

Memory for events after twenty years

This is a study of one person's memory for events that occurred twenty years earlier. Memory was observed to follow an asymptotic rate of decay. No experience of recovered memories occurred. Factors found to be related to recall were the rarity of the event, its vividness, and the emotional intensity experienced at the time. Factors unrelated or only weakly related were perceived importance of the event, its association with knowledge, and intensities of physical sensations. Pleasant events were recalled a little better than unpleasant. Though less strongly associated with memory than is location, moderate marking of events with date and time was found. The results suggest that personal memory declines as the images of events one by one submerge into the mass of generalized experiences. The more vivid, rare, and emotional experiences are more likely to remain discriminable, and may be sustained by rehearsal. Copyright © 2002 John Wiley & Sons, Ltd.     

Memory for unique personal events: Effects of pleasantness

College students recorded unique personal events for a 3-month period. At the time of recording, they rated the pleasantness or unpleasantness of the event. Subsequent memory ratings showed no effect of type of affect (i.e., pleasant vs. unpleasant events) but a strong influence of intensity of affect. In contrast, the data for estimating the date of occurrence of events showed an effect of type of affect, with pleasant events estimated more accurately than unpleasant events. A detailed analysis of the data indicated that the effect could not be attributed to the predictability of pleasant events. A red-letter day effect was proposed as an explanation for the estimation data.     

Memory for unattended events: Remembering with and without awareness

The effects of memory for unattended events—for example, events that occur while a person is asleep, anesthetized, or selectively attending to other ongoing events, as in a speech-shadowing task—are rarely revealed in tests of retention that require remembering to be deliberate or intentional. Might such effects become evident in tests that do not demand awareness of remembering? Results of the present shadowing study, involving the recognition and spelling of previously unattended homophones, suggest an affirmative answer to this question.     

Memory conjunction errors for autobiographical events: More than just familiarity

Two diary studies investigated the prevalence of memory conjunction errors for real‐life events. In both studies, participants completed detailed diary pages over the course of several weeks. Participants in both diary studies committed memory conjunction errors on a later recognition memory test. In the second diary study participants also made remember/know judgements. For a large proportion of their memory conjunction errors participants indicated that they “remembered” the event occurring in that context. These diary studies demonstrate that memory conjunction errors do occur for autobiographical memories, and these errors can seem compelling.     

Memory conjunction errors for autobiographical events: more than just familiarity

Two diary studies investigated the prevalence of memory conjunction errors for real-life events. In both studies, participants completed detailed diary pages over the course of several weeks. Participants in both diary studies committed memory conjunction errors on a later recognition memory test. In the second diary study participants also made remember/know judgements. For a large proportion of their memory conjunction errors participants indicated that they "remembered" the event occurring in that context. These diary studies demonstrate that memory conjunction errors do occur for autobiographical memories, and these errors can seem compelling.     

How eyewitnesses talk about events: implications for memory

Eyewitnesses to traumatic events typically talk about them, and they may do so for different reasons. Of interest was whether qualitatively different retellings would lead to differences in later memory. All participants watched a violent film scene; one third talked about their emotional reactions to the film (as one might do when talking to a friend), one third described the events of the film (as the police might request), and one third did unrelated tasks. Following a delay, all participants were tested on their memories for the clip. Talking about emotions led to better memory for one's emotions, but also led to subjectivity and a greater proportion of major errors in free recall. Differences were minimized on tests providing more retrieval cues, suggesting that retellings' consequences for memory are greater when retellers have to generate their own retrieval structures. Copyright © 2005 John Wiley & Sons, Ltd.     

Memory for action events in the bottlenosed dolphin

We investigated whether a bottlenosed dolphin’s ability to recall and repeat actions on command would immediately generalize to actions performed with specified objects. The dolphin was tested on her ability to repeat 18 novel behaviors performed with potentially interchangeable objects specified using an artificial gestural language. Such “action events” were correctly repeated at above chance levels, indicating that the dolphin had access to memories of those events. Performance levels were, however, lower than in previous tests. The dolphin appeared to have difficulty recalling which object an action was performed with. Previous research has demonstrated that animals can recall features of their environment and features of their actions independently of one another. The results of this study demonstrate (1) that the dolphin’s concept of repeating extends beyond simply accessing memories of movement patterns, and (2) that dolphins’ memories of past events incorporate representations of both self-performed acts and objects, locations, or gestural instructions. Received:10 October 1998 / Accepted after revision: 22 December 1998     

Memory aids people use: Two interview studies

In two interview studies subjects were asked what memory aids they used and how often. In particular, the reported frequencies of use of external aids such as shopping lists and memos were compared with those of internal aids that have been investigated by psychologists, such as the method of loci. Subjects in the first study were 15 male and 15 female university students, and in the second, a group of 30 adult women, most of whom were housewives. In both studies the aids reported to be used most were external ones. However, it is pointed out that the most commonly used methods of remembering must be internal, although these are not usually considered to be aids. Some difficulties that arise in the assessment of memory in interview and questionnaire studies are discussed.     

Memory and time

The purpose of this essay is to clarify the notion of mnemonic content. Memories have content. However, it is not clear whether memories are about past events in the world, past states of our own minds, or some combination of those two elements. I suggest that any proposal about mnemonic content should help us understand why events are presented to us in memory as being in the past. I discuss three proposals about mnemonic content and, eventually, I put forward a positive view. According to this view, when a subject seems to remember a certain event, that event is presented to her as making true a perceptual experience that caused the very memory experience that she is having.